Insertion device for intraocular lens

ABSTRACT

An insertion device for an intraocular lens is disclosed which can prevent leakage of a liquid in the device and can house and store a lens as well as the liquid. The insertion device includes a main body including a lens housing portion that houses the lens and an insertion cylindrical portion that feeds the lens into an eye, a pushing shaft that moves the lens from the lens housing portion in the front end direction to push out the lens into the eye through the insertion cylindrical portion, and a lens holding member that holds the lens, and is placed in the lens housing portion. The lens housing portion has a shape that receives insertion of the lens holding member from the rear.

BACKGROUND OF THE INVENTION

The present invention relates to an insertion device for inserting into an eye an intraocular lens that is inserted instead of a crystalline lens after the crystalline lens is extracted because of cataract or inserted into an eye in order to cure abnormal refraction.

In current operations for cataract, the central portion of the anterior capsule of an eyeball is ablated, a clouded crystalline lens is removed by an ultrasonic suction apparatus, and then an artificial intraocular lens (hereinafter simply referred to as a lens) is placed in the position of the removed clouded crystalline lens. When placing the lens in the eyeball, an operation method for inserting the lens into the eyeball through a small incision by using the flexibility of the lens and thereby deforming the lens, e.g. folding the lens into a small shape is the mainstream.

In the case of an operation, an insertion device is frequently used which deforms a lens set in a main body of the device into a small shape while moving the lens in the main body of the device by a pushing shaft and pushes out the lens into the eye from a front end opening of an insertion cylinder (nozzle) inserted into the incision. This insertion device is used not only for the operation of cataract but also for a lens inserting operation for an eyesight correction medical treatment.

When the lens is inserted into an eye by using the insertion device, a viscoelastic material such as sodium hyaluronate is introduced into the main body of the insertion device as a lubricant so that the lens is smoothly moved and deformed in the insertion device (see Japanese Patent Laid-Open No. 2004-351196). Moreover, the viscoelastic material has a function of spreading the space of the anterior chamber of the eye into which the lens will be inserted by being introduced into the eye through the insertion cylinder.

Further, it has been recently required to use inexpensive physiologic saline in place of the viscoelastic material.

However, when the main body of the insertion device is constituted by a plurality of components assembled to each other, for example, when a lens setting portion in the main body has a divided structure or an openable and closable structure, a liquid such as a viscoelastic material or physiologic saline leaks from a gap created at the assembled portion. The leaking liquid makes the insertion device slippery or soils the periphery of the device.

In the case of a conventional operation, a liquid is introduced into the insertion device immediately before the operation, which takes time and places a heavy burden on an operator or an assistant.

Further, even if the liquid such as a viscoelastic material or physiologic saline is introduced into an eye, a large amount of liquid leaking from a gap between an edge of an incision in the eye and an insertion cylinder (an amount of leakage outside the eye) prevents an increase in ocular tension and sufficient inflation of the anterior chamber.

To a pushing shaft, an elastic member such as rubber is frequently mounted for preventing a lubricant introduced into the main body from leaking from between an inner peripheral surface of the main body and the pushing shaft, and providing proper resistance (sliding feeling) to an operation of the pushing shaft.

In the conventional insertion device, the elastic member is secured to one or a plurality of points close to each other on the pushing shaft, and moved relative to the main body with the operation of the pushing shaft. This cannot prevent the pushing shaft from being inclined radially with respect to the main body around a contact position between the elastic member and the main body in the operation of the pushing shaft.

However, if the pushing shaft is inclined with respect to the main body, the front end of the pushing shaft is not precisely brought into contact with the lens placed in the main body, which may prevent the lens from being properly pushed out.

BRIEF SUMMARY OF THE INVENTION

The present invention provides an insertion device for an intraocular lens that can prevent leakage of a liquid in the device, and can house and store a lens as well as the liquid.

The present invention also provides an insertion device for an intraocular lens that can restrict the amount of leakage outside an eye of a liquid introduced into the eye through an insertion cylinder.

The present invention further provides an insertion device for an intraocular lens that can prevent inclination of a pushing shaft with respect to a main body, and can properly push out a lens.

As one aspect, the present invention provides an insertion device for an intraocular lens which comprises a main body including a lens housing portion that houses the lens and an insertion cylindrical portion that feeds the lens into an eye, a pushing shaft that moves the lens from the lens housing portion in the front end direction to push out the lens into the eye through the insertion cylindrical portion, and a lens holding member that holds the lens and is placed in the lens housing portion. The lens housing portion has a shape that receives insertion of the lens holding member from the rear.

As another aspect, the present invention provides an insertion device for an intraocular lens which comprises an insertion cylinder that is inserted into an incision formed in an eyeball and feeds the lens into the eyeball, and a pushing shaft that pushes out the lens into the eyeball through the insertion cylinder. The insertion cylinder is provided with a cover portion that is brought into contact with the eyeball to cover at least part of the incision into which the insertion cylinder is inserted.

As yet another aspect, the present invention provides an insertion device for an intraocular lens which comprises a main body in which the lens is placed, a pushing shaft that pushes out the lens from the main body into an eye, and a plurality of elastic members that are placed between the pushing shaft and the main body and have a distance changeable with movement of the pushing shaft relative to the main body.

Further objects and features of the present invention will be become more apparent from the following description of preferred embodiments with reference to the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a top view and a side view of an insertion device for an intraocular lens that is an embodiment of the present invention;

FIG. 1B is a sectional view of a lens housing portion in a main body with a nozzle of the embodiment;

FIG. 1C is a sectional view of a nozzle portion in the main body with a nozzle of the embodiment;

FIG. 2 is a top view and a side view before assembly of the main body with a nozzle and a pushing shaft of the embodiment;

FIG. 3 is a top view and a side view of a lens holding member of the embodiment;

FIG. 4 is a top view and a side view showing an assembling procedure of the insertion device of the embodiment;

FIG. 5 is a side view for illustrating a liquid introduction method into the insertion device of the embodiment;

FIG. 6 is a perspective view for illustrating the liquid introduction method into the insertion device of the embodiment;

FIG. 7 is a top view and a side view for illustrating the liquid introduction method into the insertion device of the embodiment;

FIG. 8 is a top view and a side view for illustrating the liquid introduction method into the insertion device of the embodiment;

FIG. 9 is a top view and a side view for illustrating the liquid introduction method into the insertion device of the embodiment;

FIG. 10 is a top view and a side view for illustrating a storage method of the insertion device of the embodiment;

FIG. 11 shows an incision formed in an eyeball;

FIG. 12 is a top view and a side view of an insertion device of a comparative example for the embodiment;

FIG. 13 is a top view and a side view showing a state in which a cover ring is removed from the insertion device of the embodiment;

FIG. 14 is a sectional view showing a state of an eyeball when a lens is inserted using the insertion device in FIG. 13;

FIG. 15 is a sectional view showing a state of an eyeball when a lens is inserted using the insertion device of the embodiment;

FIG. 16A is a top view and a side view of an insertion device of a comparative example for the embodiment;

FIG. 16B is a side view of a nozzle portion of an insertion device of an embodiment (a modified example);

FIG. 17A is a sectional view of a nozzle portion of an insertion device of an embodiment (a modified example);

FIG. 17B is a sectional view of a nozzle portion of an insertion device of an embodiment (a modified example);

FIG. 18 is a perspective view of a nozzle portion of an insertion device of an embodiment (a modified example);

FIG. 19 is a side view and a bottom view of a nozzle portion of an insertion device of an embodiment (a modified example);

FIG. 20 is a top view and a side view of a conventional type insertion device;

FIG. 21 is a side view and a top view of an insertion device (of a conventional type) of an embodiment;

FIG. 22 is a top view and a side view of an insertion device (of a conventional type) of an embodiment;

FIG. 23A is a side view showing an assembly completion state of the insertion device of the embodiment; and

FIG. 23B is a side view showing a lens pushing state of the insertion device of the embodiment.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Now, a preferred embodiment of the present invention will be described with reference to the accompanying drawings.

FIG. 1A shows an insertion device for an intraocular lens (hereinafter simply referred to as a lens) that is an embodiment of the present invention. The upperside in FIG. 1A shows a top view thereof and the lowerside shows a side view thereof. FIG. 2 shows a state before a pushing shaft is assembled to a main body of the insertion device. The upperside in FIG. 2 shows a top view thereof and the lowerside shows a side view thereof.

In the description below, a nozzle side is referred to as a front end side, a front or a front end direction, and a side opposite to the nozzle side is referred to as a rear end side, a rear or a rear end direction. A direction extending toward the front end side and the rear end side is referred to as an axial direction, and a direction perpendicular to the axial direction is referred to as a vertical direction, a lateral (right-and-left) direction, or a radial direction. Further, an axis parallel to the axial direction and passing through an inner space of a main body with a nozzle or the center of a lens is referred to as a central axis, and a direction around the central axis is referred to as a circumferential direction.

An insertion device 2 is basically constituted by a main body with a nozzle (hereinafter simply referred to as a main body) 12, and a pushing shaft 16. The main body 12 includes an outer cylindrical portion 12 a as a hand-held portion having an outer diameter suitable for holding the insertion device 2 by hand, a lens housing portion 12 b that is provided on the side closer to the front end than the outer cylindrical portion 12 a and houses a lens holding member 28 described later, and a nozzle portion 12 c as an insertion cylindrical portion provided on the side closer to the front end than the lens housing portion 12 b. The main body 12 is an integrally formed component (member). On the rear of the outer cylindrical portion 12 a, a flange portion 12 d is formed as a portion supported by hand when pushing the pushing shaft 16.

The main body 12 has a hollow shape, and the lens holding member 28 and the pushing shaft 16 are inserted through a rear end opening 12 i thereof.

The outer cylindrical portion 12 a has a first inner peripheral surface 12 g having a cylindrical shape from the front end thereof to a position between the flange portion 12 d and the rear end of the outer cylindrical portion 12 a. On the side closer to the rear end than the first inner peripheral surface 12 g, a second inner peripheral surface 12 m having a cylindrical shape and a slightly smaller inner diameter than the first inner peripheral surface 12 g is formed. Further, on the side closer to the rear end than the second inner peripheral surface 12 m, a conical surface 12 f is formed which has an increasing inner diameter toward the rear end. On the side closer to the rear end than the conical surface 12 f, a third inner peripheral surface having a cylindrical shape and a larger inner diameter than the first inner peripheral surface 12 g is formed up to the rear end opening 12 i.

The nozzle portion 12 c has decreasing inner and outer diameters toward the front end, and a portion from a front end opening 12 j to a predetermined length is formed to be the thinnest portion in the nozzle portion 12 c as a portion to be inserted into an eye through an incision formed in an eyeball. On an outer periphery of the rear end of the insertion portion, a cover ring (an O-ring) 13 made of an elastic member such as rubber is mounted. On the rear side of the cover ring 13 in the nozzle portion 12 c, a step 12 c 1 is formed having a larger outer diameter than the insertion portion for preventing rearward movement of the cover ring 13. The function of the cover ring 13 will be described later.

The lens housing portion 12 b basically has a section of a hollow flat plate shape having a vertical dimension smaller than a lateral dimension in axial view. A rear portion in a lower surface of the lens housing portion 12 b near a boundary with the outer cylindrical portion 12 a has a semi-conical shape having an increasing diameter toward the rear for reinforcement. The lens housing portion 12 b is inserted through the rear end opening 12 i, and thus a connection between the outer cylindrical portion 12 a and an inner surface of the lens housing portion 12 b is tapered to provide a guide configuration and facilitate insertion when the holding member 28 is inserted.

The lens housing portion 12 b can receive the insertion of the lens holding member 28 from the rear end thereof, and has an inner surface shape that can stably hold the inserted lens holding member 28.

As shown in FIGS. 1B and 1C showing sections perpendicular to an axis of the lens housing portion 12 b and the nozzle portion 12 c, respectively, peripheral walls 12 b 1 and 12 c 4 from the lens housing portion 12 b to the nozzle portion 12 c are formed as integral walls without an opening and a gap. In other words, four side (upper, lower, right and left) walls surrounding an inner space are circumferentially connected, and integrally formed without an opening such as a hole and a dividable portion or an openable and closable portion in which a gap is created in an assembled portion.

In the embodiment, the case is described where the main body 12 is produced as an integrally formed component (member) so that at least the peripheral walls 12 b 1 and 12 c 4 from the lens housing portion 12 b to the nozzle portion 12 c have no opening or gap. However, an alternative embodiment of the present invention is not limited to this case. For example, it is allowed that components divided into two upper and lower portions from the front end to the rear end may be joined by thermal welding or bonding and integrated to constitute the main body 12, and the main body 12 is thereby made as an integral component (member) without a gap at least in peripheral walls of the lens housing portion 12 b and nozzle portion 12 c after completion of the main body 12 (before insertion of the lens holding member 28). It is also allowed that the lens housing portion 12 b, the nozzle portion 12 c and the outer cylindrical portion 12 a that are formed in a divided manner are joined by thermal welding or bonding, and the main body 12 is thereby made as an integral component without a gap at least in peripheral walls from the lens housing portion 12 b to the nozzle portion 12 c after completion of the main body 12 (before insertion of the lens holding member 28).

As shown by a dotted line in the top view in FIG. 1A, a small hole 12 h is formed in a peripheral wall near the front end of the outer cylindrical portion 12 a. This hole 12 h is naturally formed for placing a member that supports a die for forming the inner surface of the main body 12 in production of the main body 12, that is, when the main body 12 is integrally formed of resin.

In the embodiment, in order to completely cover the hole 12 h, an O-ring 32 made of an elastic member such as rubber is mounted to the outer periphery of the outer cylindrical portion 12 a. Thus, the main body 12 has no opening other than the rear end opening 12 i in the outer cylindrical portion 12 a and the front end opening 12 j in the nozzle portion 12 c. Thus, as described later, the rear end opening 12 i is covered with a seal cap 14 provided on the pushing shaft 16 without a gap, and the front end opening 12 j is covered with a cap 34 described later without a gap, thereby allowing a sealed space to be formed in the main body 12 that can house a liquid such as a viscoelastic material or physiologic saline without leakage, and store the liquid with the lens 1.

A mounting surface for the O-ring 32 on the outer peripheral surface of the outer cylindrical portion 12 a has a diameter smaller than those on the sides closer to the front and rear ends. This prevents axial movement of the O-ring 32 on the outer cylindrical portion 12 a. The O-ring 32 is provided on a position often touched by hand of an operator holding the insertion device 2. Thus, the O-ring 32 has the function of covering the hole 12 h as well as the function of preventing slip of the hand holding the insertion device 2. If not covering the hole 12 h does not directly influence the flow of the liquid, covering of the hole 12 h is not necessarily required.

The lens holding member 28 includes a first holding member 28A that supports the lens 1 from below, and a second holding member 28B that retains from above the lens 1 in combination with the first holding member 28A.

First, the configuration of the lens 1 held by the lens holding portion will be described. The lens 1 has a circular shape in top view, and includes an optical portion 1 a having the function of a lens and support portions 1 b extending from the front end and the rear end of the optical portion 1 a.

The support portion 1 b is a wire-like portion that elastically supports the optical portion 1 a in the eye after the lens 1 is inserted into the eye.

A ring-shaped marginal (peripheral) portion 1 c having parallel upper and lower surfaces is formed around the optical portion 1 a. The marginal portion 1 c is hereinafter referred to as the lens marginal portion 1 c.

As shown in FIG. 3A, the first holding member 28A is formed laterally symmetrically with respect to the central axis CA passing through the center O of the optical portion 1 a of the lens 1 except part thereof. Support surfaces 28 a are formed on the right and left in the lower portion of the first holding member 28A. The support surfaces 28 a are formed as inclined surfaces whose inner portion is lower than its outer portion in the lateral direction.

In a top view in FIG. 3, a position in the front end direction from the center O of the optical portion 1 a in the lens marginal portion 1 c (a position on the central axis CA) is a 0° position. The right and left support surfaces 28 a contact arcuate regions between positions retracted by a circumferential angle of 60° to both circumferential sides (60° positions, other positions are hereinafter referred to as the same) from the 0° position in the lens marginal portion 1 c, and 90° positions retracted by a circumferential angle of 90°, and support the arcuate regions from below.

On the right and left in the axial middle of the first holding member 28A, support protrusions 28 b are formed which support arcuate regions between 135° positions to 165° positions which are regions closer to the rear than the arcuate regions supported by the support surfaces 28 a in the lens marginal portion 1 c. A space through which the pushing shaft 16 (a pushing shaft portion 16 c) passes is provided between the support protrusions 28 b. Since the space has only a 30° angle range, it may be considered that the support protrusions 28 b support an arcuate region of a 90° angle range around a 180° position in the lens marginal portion 1 c. Specifically, the first lens support member 28A supports the lens marginal portion 1 c at three points at 120° intervals including the right and left 60° positions and the 180° position.

Each of the support protrusions 28 b has a horizontal surface on which the lens marginal portion 1 c is placed and a vertical surface that contacts or is brought close to an outer peripheral end surface of the lens marginal portion 1 c on the rear side of the horizontal surface, supports the lens marginal portion 1 c from below, and prevents rearward movement of the lens 1.

Further, on the right and left on the front end side of the first holding member 28A, a vertical surface 28 e is formed that contacts or is brought close to the 60° position in the outer peripheral end surface of the lens marginal portion 1 c. The vertical surface 28 e prevents movement of the optical portion 1 a in the front end direction in a state before pushing out the lens 1.

In an upper portion at the front end of the first holding member 28A, an arm 28 c is formed extending from one side to the other side in the lateral direction (from the lower side to the upper side in the top view in FIG. 3), and at the tip of the arm 28 c, a protrusion 28 d that supports from below the front side support portion 1 b is formed to extend in the front end direction.

On the rear of the first holding member 28A, an inclined surface 28 f that supports from below the rear side support portion 1 b is formed so that its portion closer to the rear end is placed in a higher position.

Next, the configuration of the second holding member 28B will be described. The second holding member 28B is placed above the first holding member 28A. The first and second holding members 28A and 28B are inserted into the lens housing portion 12 b while holding the lens 1, and held between a ceiling surface and a bottom surface of the lens housing portion 12 b without displacement.

The second holding member 28B is formed laterally symmetrically with respect to the central axis CA, though not shown. On the right and left in a lower surface of the second holding member 28B, retaining protrusions 28 g are formed that contact or are brought close to arcuate regions from the 90° positions to 120° positions and arcuate regions from the 135° positions to the 165° positions on the right and left in the lens marginal portion 1 c. A space through which the pushing shaft 16 (the pushing shaft portion 16 c) passes is provided between the right and left retaining protrusions 28 g with the 180° position therebetween.

A portion on the front side of the retaining protrusion 28 g retains from above an arcuate region closer to the rear than the arcuate region that contacts the support surface 28 a provided in the first holding member 28A in the lens marginal portion 1 c, and a portion on the rear side of the retaining protrusion 28 g retains from above the arcuate region supported from below by the support protrusion 28 b provided in the first holding member 28A in the lens marginal portion 1 c.

As shown in a side view in FIG. 3, the second holding member 28B is assembled to the upper side of the first holding member 28A, and thus the arcuate regions from the 60° positions to the 90° positions in the lens marginal portion 1 c are supported from below by the support surfaces 28 a of the first holding member 28A, and the arcuate regions from the 90° positions to the 120° positions are retained from above by the front side portions of the retaining protrusions 28 g in the second holding member 28B. The arcuate regions from the 135° positions to the 165° positions are vertically held by the horizontal surfaces of the support protrusions 28 b provided in the first holding member 28A and the rear side portions of the retaining protrusions 28 g provided in the second holding member 28B therebetween. With such a holding structure, the lens 1 is supported in a state in which the optical portion 1 a of the lens 1 is held in a horizontal state and a stress by its own weight or an external force is not substantially applied.

The state in which a stress is not substantially applied denotes a state in which no stress is applied to the optical portion at all as well as a state in which a minute stress is applied so that a deformation influencing the optical function of the optical portion 1 a after insertion of the lens 1 into the eye does not occur even if the lens 1 is held and stored for a long time. In other words, the state denotes a state in which a stress or a deformation influencing the optical function of the optical portion 1 a does not occur.

The vertical surfaces 28 e that contact the 60° positions in the outer peripheral end surface of the lens marginal portion 1 c and the vertical surfaces of the support protrusions 28 b that contact the regions from the 135° positions to the 165° positions prevent displacement of the lens 1 in the front end direction and the rear end direction. Further, the front end side of the lens marginal portion 1 c is opened by 120° by providing the right and left vertical surfaces 28 e in the 60° positions. This allows the lens 1 to be smoothly moved from the lens holding member 28 in the front end direction in pushing out the lens 1.

On the side closer to the rear than the portions retaining the lens marginal portion 1 c of the retaining protrusions 28 g in the second holding member 28B, inclined portions are formed that extend in parallel with the inclined surface 28 f in the first holding member 28A and hold the rear side support portion 1 b together with the inclined surface 28 f.

Further, the vertical surfaces 28 e in the first holding member 28A are formed such that one of them extends in the front end direction along the outer edge of the front side support portion 1 b and the other extends in the same shape as the one. The contact of the one of the vertical surfaces 28 e with the front side support portion 1 b and the holding of the rear side support portion 1 b between the inclined surface 28 f and the inclined portions of the retaining protrusions 28 g prevent rotation of the lens 1.

In an alternative embodiment of the present invention, the configuration of the lens holding member is not limited to the above case, and any lens holding member may be allowed that can hold a lens in a state in which a stress is not substantially applied to an optical portion. The lens is not limited to one having an optical portion and a wire-like support portion, but may have an optical portion and a support portion having a flat plate shape.

FIG. 20 shows a conventional type insertion device. The upperside in FIG. 20 shows a top view thereof and the lowerside shows a side view thereof. A main body 112 of the insertion device 102 is constituted by a plurality of components including an outer cylinder 112 a, a lens holding member 112 b assembled to the front end of the outer cylinder 112 a, and a nozzle 112 c assembled to the lens holding member 112 b so as to extend from a lower surface of the lens holding member 112 b to the front end. An opening 112 h is formed in an upper surface of the lens holding member 112 b, and a lens 1 is set in the lens holding member 112 b through the opening 112 h. A cover member 124 is mounted to the lens holding member 112 b so as to cover the opening 112 h.

In this conventional type insertion device 102, gaps are created at assembled portions of the plurality of components. In the lens holding member 112 b corresponding to the lens housing portion 12 b of the embodiment, the opening 112 h through which the lens 1 is set is formed, and a gap leading to the outside from the opening 112 h is created even if the opening 112 h is covered with the cover member 124.

Thus, when a liquid such as a viscoelastic material or physiologic saline is introduced into the main body 112, the liquid leaks from the gap. Particularly, physiologic saline having a lower viscosity than the viscoelastic material leaks immediately after being introduced, and it is difficult to maintain the viscoelastic material in an amount required for an operation in the main body 112. Though the amount of leakage of the viscoelastic material is small because of its viscosity, the leakage may make the insertion device 102 slippery and is unpreferable.

As shown in FIGS. 1A and 2, the pushing shaft 16 has a D-cut shaft portion 16 a, a cylindrical portion 16 b, and a pushing shaft portion 16 c in order from the rear end side thereof. The D-cut shaft portion 16 a has a so-called D-cut shape having a section in axial view of a non-rotationally symmetric shape with a circular upper portion cut to be flat. On the D-cut shaft portion 16 a, an O-ring (a second elastic member) 43 made of an elastic member such as rubber is mounted axially movably relative to the D-cut shaft portion 16 a.

The cylindrical portion 16 b has the same or a smaller outer diameter as or than a cylindrical portion of the D-cut shaft portion 16 a, and the seal cap (a first elastic member) 14 made of an elastic member such as rubber is mounted to the outer periphery of the cylindrical portion 16 b. The seal cap 14 has a ring portion 14 a mounted on the cylindrical portion 16 b, and a conical portion 14 b having a decreasing diameter from the front end of the ring portion 14 a toward the front end. A hole through which the pushing shaft portion 16 c passes is formed in the front end of the conical portion 14 b.

The pushing shaft portion 16 c has a small outer diameter that can pass through an inner passage of the nozzle portion 12 c, and has, at the front end thereof, a lens grip portion 16 d vertically bifurcated. The lens grip portion 16 d vertically holds the rear end of the optical portion 1 a of the lens 1 held by the lens holding member 28 in the lens housing portion 12 b. This allows the lens 1 to be reliably pushed by the pushing shaft 16 in the front end direction.

In the conventional type insertion device such as the insertion device in FIG. 20, a rubber ring is mounted on an outer periphery of a pushing shaft, and the rubber ring slides relative to an inner surface of the main body with movement of the pushing shaft. However, the rubber ring is intended for providing proper sliding feeling (operation resistance) to an operation of the pushing shaft, and has no sealing function of preventing leakage of a liquid housed in the main body.

On the other hand, the seal cap 14 of the embodiment mainly has the sealing function, and is brought into press contact with the inner peripheral surface of the main body 12 by a press-contact force for achieving the sealing function, thereby also providing sliding feeling.

In the embodiment, in order to achieve the sealing function, an axial width of the ring portion 14 a of the seal cap 14 is set to 2 mm or more, and further, on the front end side of the ring portion 14 a, the conical portion 14 b is provided for preventing the liquid from leaking from the gap between the ring portion 14 a and the cylindrical portion 16 b of the pushing shaft 16. Further, in the embodiment, in a state before pushing of the pushing shaft 16 (an assembly completion state or a storage state) in FIG. 1A, the inner diameter of the second inner peripheral surface 12 m with which the ring portion 14 a of the seal cap 14 is brought into press contact in the inner peripheral surface of the main body 12 is set to be smaller than the inner diameter of the first inner peripheral surface 12 g formed on the side closer to the front end than the second inner peripheral surface 12 m. The inner diameter of the second inner peripheral surface 12 m is set to be small to increase the press-contact force with the ring portion 14 a of the seal cap 14, thereby increasing the sealing function. Specifically, as described later, the insertion device 2 can be stored so that the liquid introduced into the main body 12 does not leak. The inner peripheral surfaces 12 g and 12 m of the main body are preferably circular.

The outer peripheral surface of the ring portion 14 a of the seal cap 14 may be a simple cylindrical surface, but in order to increase the sealing function, the outer peripheral surface may have a ring shape with a semicircular section or have a plurality of ring shapes in the axial direction.

As described above, the lens grip portion 16 d that holds the upper and lower surfaces of the optical portion 1 a of the lens 1 is provided in the front end of the pushing shaft 16, and when the pushing shaft 16 is pushed in a state in which the pushing shaft 16 is rotated with respect to the main body 12, the lens grip portion 16 d cannot properly push the optical portion 1 a. Thus, particularly before pushing of the pushing shaft 16, the rotation of the pushing shaft 16 with respect to the main body 12 needs to be prevented. Further, if the pushing shaft 16 is removed from the main body 12 before pushing or after the start of the pushing, reinsertion thereafter of the pushing shaft 16 into the main body 12 is not always properly performed, and thus the removal needs to be prevented. In these views, the function required for the pushing shaft 16 of the insertion device 2 is different from a simple sealing function required for a general syringe.

Thus, in the embodiment, as described above, the inner diameter of the second inner peripheral surface 12 m is set to be small, and using an increase thereby in the press-contact force between the ring portion 14 a of the seal cap 14 and the second inner peripheral surface 12 m, that is, a friction force, the configuration is achieved in which the pushing shaft 16 is hardly rotated with respect to the main body 12 or removed from the main body 12.

In the embodiment, the case has been described where the rotation of the pushing shaft 16 with respect to the main body 12 or the removal thereof from the main body 12 is restricted using friction caused by press contact between the seal cap 14 and the main body 12, but the rotation or the removal of the pushing shaft may be restricted by other methods. For example, it is possible that the main body 12 has an inner peripheral shape similar to an outer peripheral shape of the D-cut shaft portion 16 a of the pushing shaft 16, and flat surface portions thereof contact each other to prevent rotation of the pushing shaft 16 with respect to the main body 12. A step formed between the D-cut shaft portion 16 a and the cylindrical portion 16 b (the seal cap 14) may contact a contact surface formed in the main body 12 to prevent removal of the pushing shaft 16 from the main body 12.

The relationship between the seal cap 14 and the inner peripheral surface of the main body 12 in the embodiment may be applied to the conventional type insertion device as shown in FIG. 21. FIG. 21 (the upperside shows a side view and the lowerside shows a top view) shows the configuration in which a double seal ring 44 corresponding to the seal cap 14 in the embodiment is provided in the pushing shaft 116, and the inner diameter of a portion (seal portion) with which the double seal ring 44 is brought into press contact in the inner peripheral surface of the rear end side portion of the main body 112 is smaller than that of an inner peripheral surface of a portion closer to the front end than the above seal portion.

An assembling procedure of the insertion device 2 thus configured will be described with reference to FIG. 4 (the upperside shows a top view and the lowerside shows a side view). First, the lens 1 is held by the lens holding member 28. Then, the O-ring 32 and the cover ring 13 are mounted to the outer peripheries of the outer cylindrical portion 12 a and the nozzle portion 12 c, respectively, of the main body 12. When the hole 12 h is used for introducing a liquid into the main body 12 after the assembly, it is recommended to displace the O-ring 32 to a position where it does not cover the hole 12 h.

Then, the lens holding member 28 is inserted from the rear into the lens housing portion 12 b through the rear end opening 12 i. The lens holding member 28 inserted into the lens housing portion 12 b is held by contact of the outer surface thereof with the inner surface of the lens housing portion 12 b substantially without circumferential and axial backlash.

Next, the pushing shaft 16 to which the O-ring 43 and the seal cap 14 are mounted is inserted into the main body 12 through the rear end opening 12 i. The pushing shaft 16 is inserted until the lens grip portion 16 d reaches the immediate rear of the lens 1 in the lens housing portion 12 b. At this time, the outer peripheral surface of the ring portion 14 a of the seal cap 14 is brought into press contact with the second inner peripheral surface 12 m of the outer cylindrical portion 12 a to perform the sealing function and the rotation and removal preventing function described above.

The O-ring 43 is also caused to contact the conical surface 12 f formed in the inner periphery of the outer cylindrical portion 12 a. The function of the O-ring 43 will be described later.

Into the insertion device 2 assembled as described above, a liquid is introduced such as a viscoelastic material such as sodium hyaluronate or physiologic saline (including one in which drug is dissolved) as described later. A liquid introduction method will be described below. A liquid to be introduced includes hydrophilic (water-soluble) polymer liquid besides sodium hyaluronate or physiologic saline. For example, synthetic polymer includes polyethylene glycol (PEG), polypropylene glycol (PPG), sodium polyacrylate (PAA), polyacrylamide (PAAm), sodium polystyrene sulfonate (PSSNa), polyvinylpyrrolidone (PVP), polyvinyl alcohol (PVA), polyethyleneimine (PEI), carboxymethylcellulose (CMC), dextran sodium sulfate, hydroxyethyl starch (HEPES), and polyphosphoric acid.

Natural polymer includes hyaluronate and/or sodium hyaluronate (HA), sodium alginate, dextran, dextrin, heparin, chitosan, and sodium chondroitin sulfate as polysaccharide, and polypeptide and polynucleic acid as other than polysaccharide.

Among them, polysaccharide is preferably used in view of biocompatibility or the diversity of molecular weight obtained.

Next, several methods of introducing a liquid such as physiologic saline having a lower viscosity than the viscoelastic material into the main body 12 will be described.

FIG. 5 shows a first liquid introduction method. The liquid in a syringe 35 is introduced through an injection needle inserted into the front end opening 12 j of the nozzle portion 12 c. At this time, it is recommended to mount to the nozzle portion 12 c a guide member 30 that guides the injection needle to the front end opening 12 j so as to facilitate insertion of the injection needle into the front end opening 12 j. At this time, the O-ring 32 is placed to cover the hole 12 h formed in the main body 12.

The liquid introduced into the main body 12 hardly leaks even if the front end opening 12 j is directed downward because the main body 12 has no opening leading to the outside other than the front end opening 12 j. This also applies to liquid introduction methods described below.

FIG. 6 shows a second liquid introduction method. The liquid is placed in a container 36 such as a sterile beaker, and the pushing shaft 16 is drawn rearward in a state in which the nozzle portion 12 c is inserted in the liquid. The main body 12 is sealed except the front end opening 12 j, thereby allowing the liquid to be introduced into the main body 12 similarly to the syringe.

The lens grip portion 16 d of the pushing shaft 16 needs to be inserted until it reaches the immediate rear of the lens 1 in the lens housing portion 12, and can reliably push the lens optical portion according to the position relationship thereof. Thus, in order to introduce the liquid similarly to the syringe, the configuration is adopted in which two pushing shafts are provided, a hole is formed in one pushing shaft with a seal cap 14 having no lens grip portion 16 d, and the other pushing shaft 16 having a lens grip portion 16 d can be assembled in the hole. Then, the pushing shaft having the seal cap 14 is drawn rearward in a state in which the pushing shaft 16 having the lens grip portion 16 d is fixed in the position. This allows the liquid to be introduced similarly to the syringe in a state in which the lens grip portion 16 d of the pushing shaft 16 is fixed in the position on the immediate rear of the lens housing portion 12.

FIG. 7 shows a third liquid introduction method. The O-ring 32 is displaced from the hole 12 h formed in the main body 12, the needle of the syringe 35 or a liquid supply device is inserted into the hole 12 h to introduce the liquid into the main body 12. Then, the O-ring 32 is moved so as to cover the hole 12 h. The outer peripheral surface having the hole 12 h is tapered to function as a guide in insertion so as to facilitate insertion of the front end of the needle or the liquid supply device, which further increases operability.

FIG. 8 shows a fourth liquid introduction method. In this method, a plug (a lid) 33 made of an elastic member fitted in the hole 12 h is used in place of the O-ring 32. The needle of the syringe 35 is inserted into the plug 33 to introduce the liquid in the syringe into the main body 12. The plug 33 can prevent leakage of the liquid because a hole after removal of the needle is closed by elasticity thereof. In order to prevent the plug 33 from being removed from the hole 12 h, it is recommended to devise the shape of the plug 33. For example, a portion of the plug 33 fitted in the hole 12 h preferably has an increasing thickness toward the bottom. The plug 33 may be bonded to the main body 12.

FIG. 9 shows a fifth liquid introduction method. Similarly to the third method, the needle of the syringe 35 or the liquid supply device is inserted into the hole 12 h to introduce the liquid into the main body 12. Then, a lid (a plug) 33′ is mounted to the main body 12 so as to cover the hole 12 h to prevent the liquid from leaking from the hole 12 h. In order to prevent the lid 33′ from being removed from the hole 12 h, it is recommended to devise the shape of the lid 33′. For example, a portion of the lid 33′ fitted in the hole 12 h preferably has an increasing thickness toward the bottom. The lid 33′ may be bonded to the main body 12.

If use of the insertion device without the plug 33 or the O-ring 32 does not directly influence the flow of the liquid, the use of the plug 33 or the O-ring 32 is not necessarily required.

According to the liquid introduction method described above, the liquid can be easily introduced into the main body 12 immediately before an operation or before factory shipment of the insertion device. When the liquid is introduced before factory shipment and then shipped, transported, and stored, the nozzle portion 12 c is preferably covered with the cap 34 in FIG. 10 in order to prevent leakage of the liquid outside during the shipment, transportation and storage.

The cap 34 has no opening in the front end and the peripheral wall portion, and has an opening in the rear end. A seal ring 27 made of an elastic member is mounted to the inside of the rear end. The cap 34 is mounted so that the seal ring 27 is brought into tight contact with the outer peripheral surface of the nozzle portion 12 c (or the lens housing portion 12 b) to form a closed space around the nozzle portion 12 c. Thus, even if the liquid leaks from the front end opening 12 j into the cap 34, the liquid does not leak outside. This also prevents vaporization of the liquid and damage to the nozzle portion 12 c. Thus, the lens 1 as well as the liquid can be held in the insertion device 2 and stored for a long time.

In the case of an operation, the cap 34 is removed if mounted, and the front end (a portion to be inserted into an eye) of the nozzle portion 12 c is inserted into the eye through an incision formed in an eyeball. Then, the pushing shaft 16 is pushed into the main body 12. Thus, the liquid in the main body 12 starts to be introduced into the eye through the front end opening 12 j of the nozzle portion 12 c, and the lens 1 with the optical portion 1 a held by the lens grip portion 16 d starts to be moved from on the lens holding member 28 in the front end direction. The lens 1 is folded and deformed into a small shape with movement in the nozzle portion 12 c, and pushed into the eye through the front end opening 12 j.

It can be expected that the liquid is introduced into the eye from the nozzle portion 12 c to increase ocular tension and inflate the anterior chamber, thereby forming an insertion space for the lens 1. As shown in FIG. 11, however, in a state in which the nozzle portion 12 c is inserted into an incision 15 a in an eyeball 15, the incision 15 a has a larger area than the nozzle portion 12 c, thereby creating a gap (a region outside the nozzle portion 12 c) 20 between the periphery of the incision 15 a and the outer peripheral surface of the nozzle portion 12 c. Thus, the liquid once introduced into the eye leaks from the gap 20, and in particular, when the amount of liquid introduced into the main body 12 is relatively small (for example, about 0.5 to 2.5 ml), the ocular tension cannot be increased and the anterior chamber cannot be sufficiently inflated.

Thus, in the embodiment, the cover ring 13 provided near the front end of the nozzle portion 12 c is pressed against the eyeball 15 to cover the gap 20 in the incision 15 a. In this case, the cover ring 13 may completely or partly cover the gap 20. This can restrict (prevent or reduce the amount of) the flow of the liquid from the gap 20, and even if the amount of the liquid introduced into the main body 12 is relatively small, the ocular tension can be reliably increased to sufficiently inflate the anterior chamber. When the ocular tension becomes too high, the insertion device 2 is displaced rearward so as to separate the cover ring 13 from the eyeball 15, and the liquid flows out of the gap 20 of original size, thereby reducing the ocular tension.

In this manner, according to the embodiment, the lens 1 can be inserted into the eye and also the ocular tension can be controlled simply by an operation on hand of the operator.

In the embodiment, the case has been described where the cover ring 13 as a separate member from the nozzle portion 12 c is used for covering the gap 20 in the incision 15 a in the eyeball 15, but a ring-shaped portion having the same function as the cover ring 13 may be formed integrally with the nozzle portion 12 c.

Now, the results of experiments on the functions of the cover ring 13 and a cover-ring-shaped portion having the same function and the results of experiments on optimization of the front end shape of the nozzle portion 12 c will be shown.

Experiment 1: First, as shown in FIG. 12 (the upperside shows a top view and the lowerside shows a side view), a device 19 for supplying a liquid such as physiologic saline was connected to an insertion device 2′ via a tube 18 and an experiment was conducted. At this time, the insertion device 21 did not have a cover ring 13 or a configuration corresponding thereto. A flow path through which the liquid passes was provided in a pushing shaft 16′, and the tube 18 was connected to the pushing shaft 16′.

When the liquid was continuously introduced into the eyeball from the liquid supply device 19 via the insertion device 2′ (a nozzle portion 12 c), it was confirmed that ocular tension increased and the anterior chamber was filled with the liquid, and the posterior capsule of the crystalline lens moved toward the vitreous body (the anterior chamber was inflated). It was found that when the liquid of a predetermined flow rate can be continuously supplied from the liquid supply device 19 to the eyeball, the cover ring 13 or the configuration corresponding thereto needs not to be provided in the nozzle portion 12 c.

Experiment 2: An experiment was conducted using an insertion device 2 in which a liquid of 25 ml was previously introduced into a main body 12 as shown in FIG. 13. In this experiment, a nozzle portion 12 c did not have a cover ring 13 or a configuration corresponding thereto. In this case, even if a pushing shaft 16 was pushed to introduce most of the liquid in the main body 12 into the eye, ocular tension hardly increased from ocular tension when an incision was formed, and the posterior capsule of the crystalline lens did not move toward the vitreous body. The reason that the ocular tension did not increase was studied and found. It was because the incision was linearly formed by a knife, and the three-dimensional nozzle portion 12 c was inserted into the incision to form a gap 20 in FIG. 11, and a liquid L leaked from the gap 20 as shown in FIG. 14.

Experiment 3: A cover ring 13 was mounted to the nozzle portion 12 c of the insertion device 2 used in Experiment 2, and the cover ring 13 was brought into tight contact with a portion near the incision 15 a in the eyeball 15 as shown in FIG. 15, and an experiment similar to Experiment 2 was conducted. In this case, ocular tension increased and the posterior capsule of the crystalline lens moved toward the vitreous body. It was confirmed that this was because a gap 20 is created outside the nozzle portion 12 c in the incision 15 a, but the cover ring 13 is brought into tight contact with around the incision 15 a in the eyeball 15, and thus even if the liquid flows out of the gap 20, a seal by the cover ring 13 prevents the liquid from leaking outside. In particular, the cover ring 13 has a circular section, and thus the cover ring 13 is brought into ring-shaped line contact around the incision 15 a in the eyeball 15. Thus, it can be considered that a sealing effect was able to be obtained more easily and reliably than the case of a seal by surface contact.

As described above, a step 12 c 1 was provided in the nozzle portion 12 c to prevent the cover ring 13 from moving rearward on the nozzle portion 12 c. Also, a tilt of the cover ring 13 on the nozzle portion 12 c was allowed to stably maintain a tight contact state of the cover ring 13 on the eyeball 15.

Experiment 4: As shown in FIG. 16A, a ring-shaped portion 12 c 2 having substantially the same shape as the cover ring 13 was formed integrally with the nozzle portion 12 c, and an experiment similar to Experiments 2 and 3 was conducted. In this case, the ring-shaped portion 12 c 2 had little flexibility. Thus, the ring-shaped portion 12 c 2 was able to be partly brought into tight contact with the eyeball 15, but other portions was not able to be brought into tight contact with the eyeball 15, and the liquid leaked outside from a gap between the eyeball 15 and the ring-shaped portion 12 c 2. Thus, ocular tension hardly increased.

As shown in FIG. 16B, however, it was found that a ring-shaped portion (a cover-ring-shaped portion) 12 c 3 is formed to have a thickness of about 0.3 mm and have flexibility, and thus the entire circumference of the cover ring-shaped portion 12 c 3 can be brought into tight contact with the eyeball 15, and a sealing effect equal to the seal ring 13 can be obtained.

Experiment 5: FIGS. 17A and 17B show the shape of a section of a nozzle portion 12 c of an insertion device used in this experiment. As shown in FIG. 11, when the nozzle portion 12 c having a circular section or an oval section is inserted into the incision 15 a, the incision 15 a is opened to a substantially rhombic shape. Then, gaps 20 each having a substantially triangular shape are formed between the nozzle portion 12 c and the edges of the incision 15 a.

Thus, in this experiment, nozzle portions 12 c′ and 12 c″ having protruding incision covering shapes 12 c 4 and 12 c 5 that can substantially fill the gaps 20 were formed, and an experiment similar to Experiments 2 to 4 was conducted. In this case, the gaps created between the nozzle portions 12 c′ and 12 c″ and the edges of the incision 15 a were reduced in size or eliminated, and thus the leakage of the liquid from the eyeball 15 was reduced or prevented to increase the ocular tension.

In this manner, it was found that the nozzle portion itself is formed to have the shape that can fill the gaps 20 to obtain a sealing effect equal to the case where the cover ring 13 or the cover-ring-shaped portion 12 c 3 is provided in the nozzle portion 12 c.

It is considered that a higher sealing effect can be obtained by providing the cover ring 13 or the cover-ring-shaped portion 12 c 3 in the nozzle portion having the protruding incision covering shapes 12 c 4 and 12 c 5.

Experiment 6: As in Experiments 3 and 4, providing the cover ring 13 or the cover-ring-shaped portion 12 c 3 in the nozzle portion 12 c can increase ocular tension. It is more preferable to provide the configuration for adjusting ocular tension to proper one when the ocular tension becomes too high to the contrary.

In this experiment, as shown in FIG. 18, an opening such as a hole 37 or a slit 38 was provided on the front end side of the nozzle portion 12 c from the cover ring 13 or the cover-ring-shaped portion 12 c 3. Also, an inclined portion 39 was formed in the front end of the nozzle portion 12 c.

When the ocular tension becomes too high, the insertion device 2 is slightly drawn from the eyeball so that part of the hole 37, the slit 38 or the inclined portion 39 is exposed to the outside of the eye, and thus a liquid flowing from the main body 12 to the front end opening 12 i of the nozzle portion 12 c or a liquid in the eye is ejected to the outside of the eye through the hole 37 or the like. This facilitates adjustment of the ocular tension.

For increasing the ocular tension again because it becomes too low, the hole 37 or the like may be placed in the eye to bring the cover ring 13 or the cover-ring-shaped portion 12 c 3 into tight contact with the eyeball.

Experiment 7: When the nozzle portion 12 c is inserted into a linear incision, ocular tension is still low and the incision is not opened. Thus, it is difficult to insert the nozzle portion 12 c even if the front end thereof has an inclined shape to some extent. On the other hand, merely forming the front end of the nozzle portion 12 c to have an excessively inclined shape for facilitating insertion of the nozzle portion 12 c into the linear incision increases movement resistance (friction resistance) of the lens 1 in the nozzle portion 12 c, and places an excessive load on the lens 1.

Thus, an experiment was conducted by changing the front end shape of the nozzle portion 12 c in various manners. One of the shape is as shown in FIG. 19 (the upperside is a side view and the lowerside is a bottom view). In FIG. 19, an inclined portion 41 was first provided on the lower side of the front end of the nozzle portion 12 c. A peripheral wall from the front end of the inclined portion 41 (the front end of the nozzle portion 12 c) to the rear end of the inclined portion 41 is hereinafter referred to as a front end peripheral wall T.

The front end peripheral wall T was formed over the entire circumference to be a tapered surface 40 inclined by an angle of 10° or more in a tapering direction with respect to a peripheral wall closer to the front end than the peripheral wall T. This facilitated insertion of the nozzle portion 12 c into an incision in an eyeball with low ocular tension.

On the other hand, when the inclination angle of the front end peripheral wall was 9° or less with respect to the peripheral wall closer to the rear than the front end peripheral wall, insertion of the nozzle portion 12 c into the incision was difficult.

When the tapered surface 40 having an angle of 10° or more is formed from a position closer to the rear than the rear end of the inclined portion 41, the taper excessively reduces a space in the nozzle portion to excessively increase friction resistance when the lens 1 passes through the space in the nozzle portion.

In this respect, as in this experiment, the tapered surface 40 is formed on the front end side from the rear end of the inclined portion 41 to prevent an increase in friction resistance when the lens 1 passes through the inside of the nozzle portion 12 c. Further, when the lens 1 passes the rear end of the inclined portion 41, deformation of the lens 1 is released and a stress generated in the lens 1 by the deformation is released, thereby reducing friction resistance. This facilitated insertion of the nozzle portion 12 c into the incision in the eyeball with low ocular tension, and achieved the nozzle portion 12 c with a light load on the lens 1.

Experiment 8: The configuration in which the cover ring 13 or the cover-ring-shaped portion 12 c 3 described in Experiments 3 and 4, or the protruding incision covering shapes 12 c 4 and 12 c 5 is provided in the nozzle portion may be applied not only to the insertion device of the embodiment but to the conventional type insertion device as shown in FIG. 20. FIG. 22 shows an insertion device in FIG. 20 provided with a cover ring 13 in a nozzle portion. In this experiment, a viscoelastic material was used as a lubricant.

The cover ring 13 was provided in the nozzle portion 112 c of the insertion device 102 to bring the cover ring 13 into tight contact with the eyeball 15 similarly to Experiments 3 and 4. Thus, the amount of flow of the viscoelastic material in the eye from the incision was able to be reduced.

The O-ring 43 described above is mounted on the pushing shaft 116 of the insertion device 102 in FIG. 22. In this manner, the O-ring 43 may be used in the conventional type insertion device 102 in FIG. 20.

Next, the function of the O-ring 43 will be described with reference to FIGS. 23A and 23B. As shown in FIG. 23A, in an assembly completion state of the insertion device 2 (before pushing of the pushing shaft 16), the O-ring (the second elastic member) 43 that contacts the conical surface 12 f formed in the inner periphery of the rear end of the outer cylindrical portion 12 a and the seal cap 14 (the ring portion 14 a: the first elastic member) secured to the pushing shaft 16 are close to each other. However, even in this state, the pushing shaft 16 is supported by two points: the ring portion 14 a of the seal cap 14 and the O-ring 43 with respect to the main body 12, and thus as compared with the case where the pushing shaft 16 is supported only by the ring portion 14 a of the seal cap 14, vertical and lateral displacement of the pushing shaft 16 relative to the main body 12 can be suppressed.

When the pushing shaft 16 is pushed in the front end direction in this state as shown in FIG. 23B, the seal cap 14 secured to the pushing shaft 16 is moved with the pushing shaft 16 in the front end direction, while the O-ring 43 mounted axially movably relative to the pushing shaft 16 is prevented from moving in the front end direction by the conical surface 12 f, and thus remains in a position where the O-ring 43 contacts the conical surface 12 f. This increases a distance L between the ring portion 14 a of the seal cap 14 and the O-ring 43. Thus, as compared with the state before pushing of the pushing shaft 16, vertical and lateral displacement of the pushing shaft 16 relative to the main body 12 can be minimized. Thus, the front end (the lens grip portion 16 d) of the pushing shaft 16 can be precisely guided with respect to the optical portion 1 a of the lens 1 held by the lens holding member 28, and the lens 1 can be properly pushed out.

The O-ring 43 may be mounted on the pushing shaft 16 or may be secured to the inner periphery of the main body 12. A plurality of members corresponding to the O-ring 43 may be provided rather than one. Further, a plurality of O-rings 43 are placed axially adjacent to each other, and brought into press contact with the inner peripheral surface of the main body 12 and the outer peripheral surface of the pushing shaft 16 to provide the sealing function, thus leakage of the liquid from the rear end opening 12 i of the main body 12 can be more reliably prevented in combination with the sealing function of the seal cap 14.

An elastic member corresponding to the O-ring 43 may be secured on the front end side of the main body from the seal cap on the pushing shaft so that the distance between the plurality of elastic members corresponding to the O-ring and the seal cap is reduced from a maximum state to a moderate state with the movement of the pushing shaft in the front end direction. Also in this case, as compared with the case where the elastic member corresponding to the seal cap only is provided, vertical and lateral displacement of the pushing shaft relative to the main body can be minimized, and the lens can be properly pushed out.

As described above, according to the embodiment, the peripheral wall from the lens housing portion to the insertion cylindrical portion is formed without an opening or a gap, thereby reliably preventing the liquid inside from leaking outside. Further, the lens holding member can be inserted into the lens housing portion from the rear, and thus the lens can be easily set into the lens housing portion.

Further, the lens holding member placed in the lens housing portion can reliably hold the lens in a predetermined shape, and thus the lens is not moved or deformed by the flow of the liquid in the main body, and the insertion device housing the lens can be properly stored. In this case, the need for introducing the liquid into the insertion device immediately before an operation is eliminated, thereby reducing a burden on an operator or an assistant.

The cover portion that covers at least part of the incision in the eye is provided in the insertion cylinder, and thus the amount of leakage, from the gap in the incision, of the liquid that is supplied into the eye from the insertion cylinder can be restricted. Thus, even if the amount of liquid supplied into the eye is small, ocular tension can be increased to sufficiently inflate the anterior chamber, thereby allowing the lens to be smoothly inserted into the eyeball.

Further, the plurality of elastic members are placed between the pushing shaft and the main body so that the distance therebetween is changeable with movement of the pushing shaft relative to the main body, and thus for example, the distance between the plurality of elastic members is increased with movement of the pushing shaft in a lens insertion direction. The plurality of elastic members are provided to minimize radial displacement of the pushing shaft relative to the main body. Thus, the front end of the pushing shaft can be precisely guided with respect to the lens, and the lens can be properly pushed out.

In the embodiment, a so-called preload type insertion device has been described in which the lens 1 is previously set in the lens housing portion 12 b before factory shipment (before delivery to a hospital). However, alternative embodiments of the present invention may include other types of insertion devices. For example, an insertion device in which it is stored separately from a lens and the lens 1 is set immediately before an operation can be used.

Furthermore, the present invention is not limited to these preferred embodiments and various variations and modifications may be made without departing from the scope of the present invention.

This application claims foreign priority benefits based on Japanese Patent Applications Nos. 2006-139560, filed on May 18, 2006, 2006-139561, filed on May 18, 2006 and 2006-155051, filed on Jun. 2, 2006 and each of which is hereby incorporated by reference herein in its entirety as if fully set forth herein. 

1. An insertion device for an intraocular lens comprising: a main body including a lens housing portion that houses the lens and an insertion cylindrical portion that feeds the lens into an eye; a pushing shaft that moves the lens from the lens housing portion in the front end direction to push out the lens into the eye through the insertion cylindrical portion; and a lens holding member that holds the lens, and is placed in the lens housing portion, wherein the lens housing portion has a shape that receives insertion of the lens holding member from the rear.
 2. The insertion device according to claim 1, wherein the main body includes a peripheral wall without an opening and a gap at least from the lens housing portion to the insertion cylindrical portion.
 3. The insertion device according to claim 1, wherein the main body is an integrally formed member.
 4. The insertion device according to claim 1, wherein the main body has a rear end opening through which the pushing shaft is inserted into the main body, and the lens holding member is inserted into the lens housing portion through the rear end opening.
 5. The insertion device according to claim 1, wherein a liquid can be introduced into the main body or is housed in the main body.
 6. The insertion device according to claim 5, wherein the liquid is physiologic saline.
 7. The insertion device according to claim 1, wherein the lens holding member is constituted by a first holding member and a second holding member which are allowed to contact surfaces opposite to each other of a marginal portion of the lens.
 8. The insertion device according to claim 1, wherein the lens holding member holds the lens in a state in which a stress is not substantially applied to an optical portion of the lens.
 9. An insertion device for an intraocular lens comprising: an insertion cylinder that is inserted into an incision formed in an eyeball and feeds the lens into the eyeball; and a pushing shaft that pushes out the lens into the eyeball through the insertion cylinder, wherein the insertion cylinder is provided with a cover portion that is brought into contact with the eyeball to cover at least part of the incision into which the insertion cylinder is inserted.
 10. The insertion device according to claim 9, wherein the cover portion is constituted by a separate member from the insertion cylinder, and mounted to the insertion cylinder.
 11. The insertion device according to claim 10, wherein the cover portion is tiltably mounted to the insertion cylinder.
 12. The insertion device according to claim 9, wherein the cover portion is formed integrally with the insertion cylinder.
 13. The insertion device according to claim 9, wherein the insertion device supplies a liquid into an eye through the insertion cylinder.
 14. The insertion device according to claim 13, wherein the liquid is physiologic saline.
 15. An insertion device for an intraocular lens comprising: a main body in which the lens is placed; a pushing shaft that pushes out the lens from the main body into an eye; and a plurality of elastic members that are placed between the pushing shaft and the main body, and have a distance changeable with movement of the pushing shaft relative to the main body.
 16. The insertion device according to claim 15, wherein the distance between the plurality of elastic members is increased as the pushing shaft moves in a direction for inserting the lens into the eye.
 17. The insertion device according to claim 15, wherein the plurality of elastic members include a first elastic member, the position of which is changeable with respect to the main body with movement of the pushing shaft, and a second elastic member, the position of which is unchangeable with respect to the main body with movement of the pushing shaft.
 18. The insertion device according to claim 17, wherein the first elastic member is secured to the pushing shaft.
 19. The insertion device according to claim 17, wherein the second elastic member is axially movably mounted to the pushing shaft, and contacts the main body in movement of the pushing shaft to be prevented from moving relative to the main body.
 20. The insertion device according to claim 17, wherein the second elastic member is secured to the main body. 